Dietary vitamin and carotenoid intake and risk of age-related cataract

Abstract

Background Existing studies suggest that dietary vitamins and carotenoids might be associated with a reduced risk of age-related cataract (ARC), although a quantitative summary of these associations is lacking. Objectives The aim of this study was to conduct a meta-analysis of randomized controlled trials (RCTs) and cohort studies of dietary vitamin and carotenoid intake and ARC risk. Methods The MEDLINE, EMBASE, ISI Web of Science, and Cochrane Library databases were searched from inception to June 2018. The adjusted RRs and corresponding 95% CIs for the associations of interest in each study were extracted to calculate pooled estimates. Dose-response relations were assessed with the use of generalized least-squares trend estimation. Results We included 8 RCTs and 12 cohort studies in the meta-analysis. Most vitamins and carotenoids were significantly associated with reduced risk of ARC in the cohort studies, including vitamin A (RR: 0.81; 95% CI: 0.71, 0.92; P = 0.001), vitamin C (RR: 0.80; 95% CI: 0.72, 0.88; P < 0.001), vitamin E (RR: 0.90; 95% CI: 0.80, 1.00; P = 0.049), β-carotene (RR: 0.90; 95% CI: 0.83, 0.99; P = 0.023), and lutein or zeaxanthin (RR: 0.81; 95% CI: 0.75, 0.89; P < 0.001). In RCTs, vitamin E (RR: 0.97; 95% CI: 0.91, 1.03; P = 0.262) or β-carotene (RR: 0.99; 95% CI: 0.92, 1.07; P = 0.820) intervention did not reduce the risk of ARC significantly compared with the placebo group. Further dose-response analysis indicated that in cohort studies the risk of ARC significantly decreased by 26% for every 10-mg/d increase in lutein or zeaxanthin intake (RR: 0.74; 95% CI: 0.67, 0.80; P < 0.001), by 18% for each 500-mg/d increase in vitamin C intake (RR: 0.82; 95% CI: 0.74, 0.91; P < 0.001), by 8% for each 5-mg/d increase in β-carotene intake (RR: 0.92; 95% CI: 0.88, 0.96; P < 0.001), and by 6% for every 5 mg/d increase in vitamin A intake (RR: 0.94; 95% CI: 0.90, 0.98; P < 0.001). Conclusions Higher consumption of certain vitamins and carotenoids was associated with a significant decreased risk of ARC in cohort studies, but evidence from RCTs is less clear.

The Association between Dietary Vitamin A and C Intakes and Cataract: Data from Korea National Health and Nutrition Examination Survey 2012

“…Another study in Indians also suggested that consumption of vitamin C above 66.4 mg/day was less likely to have the cataract approximately 22%, compared to the individuals consuming vitamin C less than 10.8 mg/day [ 18 ]. Meta-analyses also confirmed such protective effect of vitamin C in Asian and US populations [ 19 ], and, in randomized controlled trials [ 6 ].…”

“…A meta-analysis provided the comprehensive evidence that consuming sufficient amount of vitamin A reduced the risk of cataract by 17% (95% CI, 0.757–0.913) [ 4 ]. Another recent meta-analysis also reported the significantly reduced risk of cataract by the consumption of vitamin A and carotenoids: for vitamin A (relative risk [RR], 0.81; 95% CI, 0.71–0.92), and for beta-carotene (RR, 0.90; 95% CI, 0.83–0.99) [ 6 ].…”

“…Vitamin A and carotenoids are known to attenuate the UV-induced oxidative stress by reducing of reactive oxygen. This neutralizing effect of vitamin A and carotenoids is therefore protective against eye disorders, especially cataract [ 6 ]. Studies suggested that higher serum level of retinol significantly reduced the risk of cataract [ 5 ].…”

Dietary Patterns, Carbohydrates, and Age-Related Eye Diseases

“…Age-related cataract has also been associated with vitamin and carotenoid status [ 6 , 7 ]. Although nutrients such as vitamins A, C, and E, lutein, zeaxanthin, and β-carotene were associated with reduced cataract risk in cohort studies, inconsistent results are reported in RCTs [ 8 ]. Observational cohort studies suggest that regular consumption of nitrate-rich leafy green vegetables is associated with reduced risk of glaucoma development [ 9 ].…”

Association between Dietary Vitamin A and HPV Infection in American Women: Data from NHANES 2003–2016

“…eir vitamin A consumption does not meet the estimated average demand (EAR) or adequate intake (AI) of the Institute's dietary reference intakes (DRIs) [3]. Evidence from previous studies suggested that insufficient intake of vitamin A can cause numerous diseases, for example, HPV infection, obesity, and visual impairment [4][5][6]. erefore, the government tried to change the status of micronutrient deficiencies such as vitamin A through the enrichment and/or fortification (E/F) of food supply policy [7].…”